From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9778FC04AAA for ; Fri, 3 May 2019 16:49:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 722272075E for ; Fri, 3 May 2019 16:49:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728569AbfECQtL (ORCPT ); Fri, 3 May 2019 12:49:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:39242 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728056AbfECQtL (ORCPT ); Fri, 3 May 2019 12:49:11 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0C20B2075C; Fri, 3 May 2019 16:49:07 +0000 (UTC) Date: Fri, 3 May 2019 12:49:06 -0400 From: Steven Rostedt To: Andy Lutomirski Cc: Peter Zijlstra , Linus Torvalds , Linux List Kernel Mailing , Ingo Molnar , Andrew Morton , Nicolai Stange , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "the arch/x86 maintainers" , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , Shuah Khan , Konrad Rzeszutek Wilk , Tim Chen , Sebastian Andrzej Siewior , Mimi Zohar , Juergen Gross , Nick Desaulniers , Nayna Jain , Masahiro Yamada , Joerg Roedel , "open list:KERNEL SELFTEST FRAMEWORK" , stable Subject: Re: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions Message-ID: <20190503124906.576c21f7@gandalf.local.home> In-Reply-To: References: <20190502181811.GY2623@hirez.programming.kicks-ass.net> <20190502202146.GZ2623@hirez.programming.kicks-ass.net> <20190502185225.0cdfc8bc@gandalf.local.home> <20190502193129.664c5b2e@gandalf.local.home> <20190502195052.0af473cf@gandalf.local.home> <20190503092959.GB2623@hirez.programming.kicks-ass.net> <20190503092247.20cc1ff0@gandalf.local.home> <2045370D-38D8-406C-9E94-C1D483E232C9@amacapital.net> <20190503123126.3a2801be@gandalf.local.home> <20190503163527.GI2606@hirez.programming.kicks-ass.net> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 3 May 2019 09:44:35 -0700 Andy Lutomirski wrote: > On Fri, May 3, 2019 at 9:35 AM Peter Zijlstra wrote: > > > > On Fri, May 03, 2019 at 12:31:26PM -0400, Steven Rostedt wrote: > > > I guess the real question is, what's the performance impact of doing > > > that? > > > > Is there anyone that considers i386 a performance platform? > > Not me. As far as I'm concerned, I will basically always gladly trade > several cycles for simplicity on 32-bit. > So should I wait for a new PATCH 1 from Peter to implement it this way? I'd like to get this into the next merge window (although, I am marking it for stable since it fixes a bug for live kernel patching). Linus, what's your thoughts? -- Steve